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Message-ID: <64bb37e0801060335k4afb3134u9c6fadb57d525dc5@mail.gmail.com>
Date: Sun, 6 Jan 2008 12:35:35 +0100
From: "Torsten Kaiser" <just.for.lkml@googlemail.com>
To: "FUJITA Tomonori" <tomof@acm.org>
Subject: Re: 2.6.24-rc6-mm1
Cc: akpm@linux-foundation.org, jarkao2@gmail.com, herbert@gondor.apana.org.au,
       linux-kernel@vger.kernel.org, neilb@suse.de, bfields@fieldses.org,
       netdev@vger.kernel.org, tom@opengridcomputing.com,
       fujita.tomonori@lab.ntt.co.jp
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On Jan 6, 2008 12:23 PM, FUJITA Tomonori <tomof@acm.org> wrote:
> On Sun, 6 Jan 2008 11:41:10 +0100
> "Torsten Kaiser" <just.for.lkml@googlemail.com> wrote:
> > I will applie your patch and see if this hunk from
> > find_next_zero_area() makes a difference:
> >
> >        end = index + nr;
> > -       if (end > size)
> > +       if (end >= size)
> >                 return -1;
> > -       for (i = index + 1; i < end; i++) {
> > +       for (i = index; i < end; i++) {
> >                 if (test_bit(i, map)) {
>
> The patch should not make a difference for X86_64.

Hmm...
arch/x86/kernel/pci-gart_64.c:
alloc_iommu() calls iommu_area_alloc()
lib/iommu-helper.c:
iommu_area_alloc() calls find_next_zero_area()
-> so the above code should be called even on X86_64

And the change in the for loop means that 'index' will now be tested,
but with the old code it was not.

And double using something does fit with the errors I'm seeing...

> Can you try the patch to revert my IOMMU changes?
>
> http://www.mail-archive.com/linux-scsi@vger.kernel.org/msg12694.html

Testing for this bug is a little bit slow, as I'm compiling ~100
packages trying to trigger it.
If my current testrun with the patch from
http://www.mail-archive.com/linux-scsi@vger.kernel.org/msg12702.html
crashes, I will revert the hole IOMMU changes with above patch and try again.

Torsten
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